Re: [ILUG] CORRECTION - How to copy some files

From: Brian Foster (blf at domain utvinternet.ie)
Date: Fri 19 Jul 2002 - 21:01:54 IST


  | Date: Fri, 19 Jul 2002 16:15:49 +0100
  | From: Brian Foster <blf at domain utvinternet.ie>
  |[ ... ]
  | the issue here is tar(1) (and cpio(1)) archives always
  | contain the data for each name of a hard link. [ ... ]

 ARRGGGHHHH!!!!!
 profuse apologies, the wrong version of my reply was posted
 (blame it on being late for the pub). ;-(

 the above is almost pure B*S* --- I got my `tar's and `cpio's
 confused. what I said _is_ correct, but for cpio(1) archives;
 tar(1) archives do _not_ replicate the data for hard links.

 I spotted this confusion on my part before I posted my reply,
 and re-wrote it to be more correct, yet somehow the wrong
 version got sent anyways. ARRGGGHHHH!!!!! ;-( ;-( ;-(

 anyways, GNU `cpio -p' does not do spurious reads or writes.
 GNU `tar cf - ... | tar xf - ...' also does not, albeit each
 `tar' both reads and writes the data. hence, there is twice
 (not thrice!) the I/O of `cpio -p', maybe an issue for c.60Gb.

 using strace(1), I've verified my claim GNU `cpio -p' does
 not do spurious reads or writes, i.e. it link(2)s. but having
 just come back from the pub, perhaps this should also be taken
 with extra skepticism ...... ;-\

sorry. cheers!
        -blf-

--
 Innovative, very experienced, Unix and      | Brian Foster    Dublin, Ireland
 Chorus (embedded RTOS) kernel internals     | e-mail: blf at domain utvinternet.ie
 expert looking for a new position ...       | mobile: (+353 or 0)86 854 9268
  For a résumé, contact me, or see my website  http://www.blf.utvinternet.ie
    Stop E$$o (ExxonMobile):  «Whatever you do, don't buy Esso --- they
     don't give a damn about global warming.»    http://www.stopesso.com
     Supported by Greenpeace, Friends of the Earth, and numerous others...


This archive was generated by hypermail 2.1.6 : Thu 06 Feb 2003 - 13:17:59 GMT